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Rock Bass (Ambloplites rupestris)

Rock bass


rock bass

Rock bass are aggressive predators and can become a nuisance to anglers targeting smallmouth bass.

NH Conservation Status: Not listed


State Rank: Exotic


Distribution: The rock bass is native to the Great Lakes and Mississippi River drainages. It is has been widely introduced into waterbodies throughout New Hampshire.


Description: The rock bass is a member of the sunfish family with a large mouth that extends beyond the middle of the eyes. It is brass to olive brown in color with horizontal rows of dark, roughly square shaped spots. The large eyes are often reddish in color. Rock bass usually grow to about 8 inches in length, and rarely exceed 12 inches.


Species commonly confused with: Bluegill, white perch


Habitat: Rock bass are found in the shallow margins of lakes, ponds, and larger rivers where they usually prefer rocky substrate mixed with areas of sand and gravel.


Life History: Spawning occurs in the late spring as the temperature warms to between 60° and 70°F. Females lay an average of 5,000 eggs in gravel depressions excavated and defended by the males. Rock bass feed mainly on small fish, crayfish and other small aquatic invertebrates. Under favorable habitat conditions, rock bass can become extremely abundant.


Origin: Introduced


Conservation/Management:Rock bass are considered an invasive species that, once introduced, is capable of altering the food web in lake and pond ecosystems.




  • Discourage the spread of rock bass through illegal introduction into new waterbodies. Once established, rock bass are virtually impossible to eradicate.